I wonder how do you bolt things to the metal.. do you drill, do I need to take off the cloth cover, etc?I bolted particle board shelving to the rear seat back in my Civic (made of metal) and used t-nuts and machine screws to hold the amplifiers in. MDF should work just fine too.
I tried mounting an amplifier directly to the rear seat back in my 2006 rustang (made of composite) and ended up hearing a bang one day while driving because the amp worked itself loose from the plastic.
Well I don't think many people have to worry about drilling into the gas tanks built into their rear seats.Be careful of drilling into metal that you dont hit gas lines or other things. I once put a hole through a gas tank like that